An operating system can be used to govern operations of a computing device and regulate use of hardware of a computing device, among other functions. To do so, the operating system is loaded from a storage drive accessible by the computing device, after which a processor of the computing device executes the operating system instructions. Multiple different types of storage drives can be used to store an operating system.
For example, an operating system can be stored in an internal storage device of a computing device, which could be a hard disk drive (HDD) or a solid-state drive (SSD). Such internal storage devices are hardware resources that are fixed components of computing devices. As fixed hardware resources, the internal storage drives may be configured to be used with only a single computing device. Such fixed hardware resources may be attached to a computing device in several different manners, including by being removably coupled to the computing device and being disposed inside a housing of the computing device.
Another type of storage drive that may be used to store an operating system is a portable storage drive. A portable storage drive is not a fixed resource of any particular computing device. A portable storage drive is not uniquely associated with any particular computing device. Rather, multiple different computing devices may be used as host machines for the portable storage drive without changing a configuration of the portable storage drive and/or without changing a hardware configuration of the computing devices with which the portable storage drive is used. Such a portable storage drive may be used with multiple different computing devices without negatively affecting any of those computing devices when the portable storage drive is not present, in that the computing devices may still be operable when the portable storage drive is not present. In some cases, a portable storage drive may be bootable, in that the portable storage drive may include a boot sector that may be read by boot firmware of a computing device as part of bootstrapping a computing device and loading an operating system.
Where such portable storage drives are to be used with physical computing devices, the portable storage drives may be physical hardware. One example of a portable storage drive that is physical hardware is a flash memory drive adapted to interface with a computing device via Universal Serial Bus (USB). Portable storage drives may also be used with virtual computing devices (also called virtual machines) and, in these cases, may themselves be virtual. One example of a portable storage drive that is virtual is a virtual hard drive (VHD) that can be associated with one or more virtual computing devices and used to store information for the virtual computing device(s).
A portable storage drive may store an operating system that is also portable, in that the operating system is not uniquely associated with hardware of any particular computing device that may act as a host machine for the operating system. Such an operating system can be used with multiple computing devices without substantially changing the configuration of the operating system. By not substantially changing the configuration of the operating system, even while or after the operating system is used with a different computing device, the operating system may remain operable with other computing devices. In some cases, the operating system may be adapted for use with multiple different hardware configurations.
When a computing device is to act as a host machine for an operating system stored on a portable storage drive, the computer-executable instructions for the operating system may be loaded from the portable storage drive into another storage of the host machine, including one or more internal storage devices like system memories, and may be executed by one or more processor(s) of the host machine. By doing so, the host machine may be operated and governed by an operating system that is not originally retrieved from an internal storage device of the host machine, but is instead originally retrieved from a portable storage device. This might be useful in some environments where, for example, a user wants to use the portable operating system with the host machine for only a short time, without replacing the usual operating system of the host machine that may be stored on an internal storage device.
One example of a portable operating system that can be used with portable storage drives is the WINDOWS TO GO™ system available from the Microsoft Corporation of Redmond, Wash.